1) Field of the Invention
The present invention relates to a shock-absorbing air bag. More particularly, the present invention relates to a shock-absorbing air bag comprising a woven fabric having a high flame resistance, a light weight and a preferable air-permeability and folding capability.
2) Description of the Related Art
It is known that a conventional shock-absorbing air bag is produced by a sewing procedure from at least one woven fabric having a plain weave or twill weave structure, composed of warps and wefts each comprising a high strength nylon 6, nylon 66 or polyester multifilament yarn having a total denier of 400 to 1000, and coated with an elastomer resin, for example, a chloroprene rubber or silicone rubber. This type of air bag is disclosed in, for example, Japanese Examined Patent Publication No. 48-30293 and Japanese Unexamined Utility Model Publication Nos. 48-81543 and 51-117936.
The woven fabrics for the conventional air bags exhibit a high heat resistance and flame resistance, and the air bag is arranged between a steering wheel and a front seat for a driver or pilot of an automobile or aircraft, and is quickly inflated by a blast of a combustion gas generated in and blown from an inflater when the automobile or aircraft is in an accident. Accordingly, the air bag must exhibit a satisfactory resistance to a high temperature and the pressure of the combustion gas blast; namely, the air bag must satisfy a safety standard set for the air bag, and accordingly, the woven fabric for the conventional air bag is coated with an elastomer resin layer in a large basis weight.
This heavy and thick coating layer causes the woven fabric for the air bag to become stiff and makes it difficult to sew and handle, and further, the resultant air bag has a undesirably large volume when folded.
The air bag must be arranged in front of the driver or pilot to protect him or her from damage, but the space in front of the driver or pilot is equipped with a steering wheel, various instruments and a window, and thus the space in which the air bag can be accommodated is very restricted, and accordingly, the air bag must be able to be compactly folded and received in such a restricted space. Also, when installed at a steering wheel, the air bag must be as light as possible.
Further, when the combustion gas blast is blown into the air bag, a portion of the combustion gas blast is blown under a high pressure from the air bag through a pair of vent holes each having a diameter of about 30 mm and formed in the air bag, and this blown portion of the combustion gas blast sometimes impinges on a person or persons in the automobile or aircraft.
Accordingly, a new type of air bag not having a vent hole is required.